Fluid-pressure-operated device



Sept. 11,1928. v 1,684,063

T. s. MILLER FLUID PRESSURE OPER'ATED DEvIcE Filed Aug., 1, 1924 2 sheets-sheet 4 2 ff' if ffl f7 .f7 ff f-79 y INI/Enron.

. l AzToRNEYAv f Patented Sept. l1, 1928 UNITED STATES PATENT oFFlcE..

. THOMAS SPENCER MILLER, OF SOUTH ORANGE, NEW JERSEY. .I

FLUID-PRESSURE-OPERATED DEVICE.

Application led Aug-ust 1, 1924. Serial No. 729,462.

I have illustrated'in the accompanying drawings one form `of apparatus embod ing one feature of my invention, and by w ich.

the method may be carried out. y My invention will be best` understood by reference to the accompanying drawings, in which Fig. 1 is a perspective view illustrating my inventionin connection with a fluid pressure operated clutch and a fluid pressure m operated brake; Fig. 2 is a longitudinal section through a fluid pressure operated device formed and operated in accordance with my invention; Fig. k3 is a plan view of the two valve members controlling the fluid '5 under pressure to the respective fluid pressure 4operated devices; Fig. 4 is a side view of Fig.- 3; Fig. 5 is a sectional view through one of the valve members controlling the fluid pressure to the fluid pressure operated '20 device; Fig. 6 is a sectional view through the operating handle for one of the valves, andFig. 7 is a sectional view through the fluid pressure operated device illustrated in Fig. 1 which actuates the brake.

Like reference characters indicate like parts throughout the drawings.

In Fig. 1, I have illustrated my invention in'connection with a fluid pressure `operated friction device, illustrated generally at 10, l and a fluid pressure operated'friction brake,

as at 11, associated with a hoisting drum 12.

The drum 12 is provided with a flange 13 whichis engaged by the friction band 14.

. One end of the friction band 14 is connected l5 by means of a bolt 15, between the ends of two arms 16 secured on a shaft. 17, having its bearings in the frame 18 of the device. The shaft 17 is rocked by an arm 18EL secured on the end thereof and' operated by a piston i 19' in a cylinder 20, the piston being connected to the end of the arm 18n by a piston stem 21. The movement of the piston 19 to the right, as viewed in Figs. 1 and 7. rocks the shaft 17 in a direction to apply the friction 5 brake. The movement of the piston 19 to the-right by steam pressure is resisted by an expansion spring 22, which tends to move the piston to the left. Steam is admitted to the left end of thecylinder 20 through a "l0 steam supplypipe 23. An operating gear 24 is provided with a friction cone 25 with whichengages. a friction member 26 on the flange 13.

I .s The friction `device v1 is operated a. .,5 fluid.. pressure operated device, indicated genera at 27. AThedrum 12A is longitudinally movable on the shaft '28. The uid pressure operated device 27 illustrated, comprises a cylinder 29 closed at one end byA a v plate 30, which lmay be integral with the c 1- mder and at the opposite end by a remova le plate 31 secured to the cylinder Aas by bolts 32. The cylinder'29 is, in the form illus'- trate'd, securedto the end of the shaft 28 by a screw-threaded connection 33. Within the 28 in the shaft. and engages a cross key 37 arranged in a slot transversely of the shaft 1n a known manner, the key 37 enga ng the drum the left so that a movement thereof to the rlght forces the drum to the right and the friction member 26 thereon into engage-l ment with the friction member on the gear 24. Movement of the piston 34 to theright is resisted by a plurality of springs 27'.'L (only one of which is shown in Fig. 2), which are interposed between the piston and sesV the right hand end of the cylinder 29 and tend tovmove the piston to the left, as viewed in Fig'. 2. As the cylinder 29 is secured on the shaft-28 on lwhich the gear 24 is also secured, the cylinder (with the piston) normally rotates.

In accordance with one feature of my invention, novel means are provided for supplying steam to the cylindet` 29 and for eX- haustingl leakage steam therefrom. It has been found in practice that a considerable amount of steam leaks past the piston i to the cylinder beyond the piston. It as hitherto been proposed to provide ahole in the back of the cylinder to remove such leakage steam. The presence of this steam,

however, in the space occupied by the operator clouded his vision and caused annoyance. In accordance With my invention, the ste-am leaking past theipiston' and into the cylinder is conducted to a point remote from the space occupied by the operator and where its presence cannot interfere with his In the embodiment of my invention illustrated, a tubular member 38 is attached to and forms a tight fit withinv the o ning 31* in the middle portion of the en V the connections being such as to permit relavision, or otherwise interfere with his work.v4

.tive rotary movement. between the tubular member 38 and the cylinder, the tubular member being stationary and the cylinder being rotary, as already stated. The end plate 31 is preferably provided lwith an outwardly extending central flange 39 spaced from the tubular member 38, and in which is. received a stuffing box 40. Within the tubular member 38 and spaced therefrom for the major portion of the latter, as illustrated in Fig. 2, is a tube 41, the inner end of which is screwedinto and made fast to the piston as by a screw-threaded joint 42. The outer end of the pipe-41 communicates with a chamber 42a, formed in a head or casing 43, and with which also'communicates a pipe 44 which'leads to a point remote from the space occupied by the operator and preferably to an ash pit of the boiler. This pipe 44 isdiagrammatically illustrated in Fig. 1 as leading Abeyond a partition 45a to a space 46a, the space occupied by the operator being indicated generally at 47a.

Steam is preferably supplied to the cylinder by a steam supply plpe which communicates with the annular space 46 between the tubular member 38 and the pipe 41, said annular space leading' to the cylinder 29. The pipe 41 communicates with the portion of the cylinder at the `right of the piston 34 by means ofv a chamber 47 and radial passages 48 leading from said chamber through the hub 49 -on the piston. Any steam, therefore, which leaks past the piston into the cylinder flows through the passages 48, chamber 47, pipe 41, chamber 42a'and ipe 44 to the space beyond the operator. n outlet pipe44a is connected to the cylinder 2O and carries the' leakage steamv therefrom to a point remote from theoperator. lf an insuiicient amount of steam Hows past the piston to preheat the cylinder and prevent ycondensation of steam, apiston ring may be removed or the piston may be provided with a small opening in the head.

vNot only is the steam which leaks past the piston led to a point remote from the space occupied by the operator, but in accordance 1 with my invention, steam or other heated .fluid under pressure is normally admitted to the cylinder in an amount which is insufficient to voperate the piston against the resistance offered by the springs 27, but suicient in: amount to maintain the cylinderV and the piston, 4through leakage, in a warm `condition 4and to prevent condensation of steam in the cylinder.

The valve members, indicated generally in Fig. 1 by the reference characters 50 and 50, which control the supply of fluid under pressure to the respectlve c linders 20 and 29 oth valve members are, or may be the same vin construction and operation, and the description of one will suffice for both. The valve member 50ccmprises a valve casing 51 provided with a cates, the supply pipe 23 for the fluid presl sure operated device 2O being connected to said port 53. The valve casing is also.pro.

vided with a port 54 also communicating with the chamber 52 and by means of which fluid under pressure is supplied through the chamber 52 and port 53 to the supply pipe 23. The valve casing is also provided with a longitudinal bore 55, which, at one end,

vcommunicates with said chamber 52 and at chamber 52 with which a port 53 communi- I the other end opens into an exhaust or relief chamber-56 which opens to the atmosphere through a port 57 and pipe 58. Slidably disposed in the bore 55 1s a cylindrical hollow valve member 58, the bore vof which opens at one end into the chamber 52, while ,the opposite end thereof opens into the relief chamber 56. The right hand end of the valve member 58a, as viewed in Fig. 5, projects into the chamber 52 and is provided with a valve head 59, preferably provided with a conical face 60, adapted to cooperate with a valve seat 61 formed at the juncture of the chamber 52 withthe bore 55. The 'valve member 58a is -provided near the head 59 with an annular peripheral groove 62. The parts controlling and operating the valve member 58a are preferably constructed and arranged normally to maintain the valve head 59 slightly spaced from'the seat 61 on the casing, as ,illustrated in Fig.' 5, so as normally to admit a small amount of steam from the supply pipe to the fluid pressure operated device, and when the valve is entirely unseated, the pressure medium flows freely from the port `54 through the groove 62 and thence into the chamber 5 2 and out through the port 53 and pipe 23 to the fluid pressure operated device 20. The valve is normally moved towards seat by an expansion coil spring 64 located in the chamber'52, and the ends of which abut respectively against the 58? and a head 65, which is preferably screwed into and closes the end of the, casing 51. At the end of the casing .51 oppo site that vcontaining the chamber52, isa bore 66, preferably larger than the bore 55,' with a vcontracted portion at 67 concentric with the bore 55 and which is separated therefrom and from the relief port 57 by a wall 68, provided with a central circular opening 69 in whichis slidablydisposed a cy# lindrical valve block 70, preferably of a length greater than the thickness of said wall 68. One end of the member 70 is provided with a @valve seat 71, against which the valve member 58a is seated, and which is preferably secured t0 the member 70 by a screw 73. The end of the bore through the valve member k58a adjacent to the seat 71 is preferably flared, asy indicated at 74.

vocated inthe bore 66 of the valve casing is a hollow piston `or head 75, open at one end of the valve member end and closed at the lot/her' end. A @Oil spring 76 is partially'enclosed in the piston and seated at one end against the end wall off the piston, while the opposite end thereof surrounds a head or plunger 77,

preferably provided at one end with a ianged head or collar 78, against which the opposite end of the spring 76 is seated, and

.which engages the end of the member 70,

the spring 76 normally exerting its expansive force to push the member 70 to the right, as viewed in Fig. 5, into engagement with the' adjacent end4 of the valve member 'as the shaft 80. A cam 82 is secured on the shaft 8O and engages the closed end of the piston 75 to compress the spring 76 to a greater or less extent.

'I have applied to the valve member 50a vthe same reference characters to parts c0rrespondingto those of the valve member 50, but with the letter a appended. A cam 82'dl is mounted on its shaft having its bearings in the ears 7 9a of theivalve casingOa in the same or similar manner as the corresponding parts described in connection with the valve member 50.

Preferably both of the valves are simul- L thevalve head 59 against the seat 61 and taneously operated by manna? means, operated either by the hand or loot, and here illustrated as a yhand lever 81, in a manner whichwill nowl be described. The handle is mounted on la body portion 84 to which it is secured by a pin 83, and passes through and isguided by a slot 85 in 'a stationary quadrant 86. On the lower portion of the handle is mounted a member 87 (Fig. 1) flared outwardly as indicatedY in Fig. 1, into a flange 88 by means of whichyboth cams 82 and 82a are simultaneously operated by the movement of the handle 81 and generally in reverse directions. .Y On the shafts 80 and 8Oa are secured arms 801 and 802 connected to the flange 88 by bolts 89 and 89a, which pass through openings inV said viiange, so that the operation ot the hand lever 81 simultaneously rotates both cam members 82 and 82a, and preferably infopposite directions, as stated. rlhe handle iss.

provided with a rod 90 extending longitudinally thereof and provided atits outer end with a plunger 91, by which the rod maybe depressed, a coil spring 92 being interposed between the head'91 and the shoulder 93 lormed at the lower end of a longitudinal opening 94 in the handle. The lower end of the rod 90 is rovidedwith a latch member which exten s laterally from the handle and rides along the lower faces of the two sides of the quadrant, as best showninlFig. l

70 is adapted to lock the handle in any desired. position. It will, of course, be understood 4that any desired number of said notches may be employed.

Generally, the cams 82 and 82a will be so mounted on their shafts that the cam portions will be oppositely directed. With thev parts so arranged, when the handle is in the middle or neutral position, the cams 82 Vand 82.n may be so adjusted on their shafts that both valves will be only slightly open to admit steam to the respective cylinders in an amount sufficient to maintain the cylinders and pistons, through leakage, in a warm condition, but insuliicient in amount to operate the pistons. Assume, for example, that the'l parts are set to maintain at this time a. pressure of live pounds in the cylinders. Considering the valve member 50, shown in Fig. 5, in case the pressure in the cylinder 20 builds up tol an amount above five pounds, then the pressure of the ril) steam against the valve seat 71 will force A' this valve seat and the member 70 toward th-e lett against the action of the spring 7 6.

(It must be understood that the pressure in' the hollowv portion otvalye 5.8a is always the same as that in cylinder 20). At, the same time, valve member 58a is forced to the left .aided by spring 64, thereby vseating thereby permitting the excess pressure to beexhausted through port 57.

On the other-hand, in the event that the steam pressure in the cylinder 20alls below live pounds, then the steampressure against thevalve seat 7l being lessened,

the spring 76 forces the member 70 and the valve seat 71 to theright, as viewed in Fig.

steam to pass vthrough the port 54 by the valve seat 6l into chamber 52 and to the port 53 (leading to the cylinder 20), there by building up the pressure to the desired live pounds.A In lother' words, when the parts aire set `at avpredetermined pressure, then any building up of pressure in the cylinder substantially above that in whiclrthe valve is set, causes the excess steam to exhaust from the cylinder through port 57. Any substantialreduction of the steam pres sure in the cylinder below the desired amount causes the valve head 59 to be opened further, increases the flow o'steam from Excess steam is then 5, thereby opening the valve and permitting thesupply pipe to the cylinder, thereby bringing the pressure back to the desired amount. It is to be understood that the ffunction of the spring-64 is merely to ush the valve member 58 to the leftand old the valve head 59 against its'seat especially vwhen there is no pressure in ,chamber 52.

rlhere is no necessary relation between the'. "relative stren th of this spring 64 andthat vof the spring 6, except that it is far weaker than the spring 76. When the handle 81 is moved in one direction, as to the left, as viewed in Fig. 1, the cam 82 will be rotated i anti-clockwise, as viewed in Fig. 4, and move let wes-

ber 58a in the nearly closed position,

in the position indicated in Fig. 5.- When' -thecam member 82 is rotated anti-clockwise its pistonx tothe right which, in turn, moves the valve member 58a, to theright yagainst the 4action of' the `spring 64E-te rapen the same and admit more fluid under-pressure from the supply pipe 95, port 54, through the groove 62, chamber 52 and port 53 to the-pipe 2.3, leading to the cylinder 20. At thesame time, the other cam -82-will be further moved away from its piston 7 5@ thereby retaining the valve memand as viewed in Fig. 5, and the valve-member 58a thereby moved to the right in the manner described, the additional fluid pressure admitted to the cylinder l20 causes the .piston to be actuated, 4and the device is set at a given pressure depending` upon the position ofthe lever` 81, for example, if it is 'desired to operate the device,'and maintain the steam pressure inthe cylinder 20 at 150 pounds, then the lever will be moved to'a corresponding position.y Then any increase pressure is brought down to the desired 150 pounds when the spring v7 6 will again move the member 70 and the valve member 58 to the right. Similarly, in case the lpressure falls below 150 pounds, the spring .76 will push the member 70 and the valve member 5'8",L to the right (since the pressure against the valve seat 71 is now decreased),-

and .thereby more fully open the passage leading from the source of steam supply past the valve head 59 and to the steam cylinder, 'and this will continue until the steam pressurehas again built up to the desired 150 pounds. The operation -of the valve member 58- and the associated parts -w-ill, of course, be the same for 4intermediate' pressures..H c

' tons,

Leganes On the other hand, when the handle 81 is moved to the right, as viewed in Fig. 1, the cam 82@- is rotated clockwise to move the'associated piston'7 5 to the right and similarly open communication between the.

supply ipe and the pipe 45 to admit fluid unt er pressure to the cylinder 29, the other valve of the valve member 58 remaining nearly closed during this operation. Not only does the valve member l51 (51a) illustrated control the admission of fluid under pressure to the fluid pressure operated device,

'This may be donev byoperating the lever 81 in such a direction that the tension on the lspring 7 6 is weakened This will cause the',

pressure medium which acts through the hollow valve 58 upon the member 70 to depress the, member, ,thereby permitting the. pressure medium to exhaust through the port 57 andthe pipe 58 (Fig. 1). `By so controlling the exhaust of fiuid4 pressure, slippage either of the friction device or of the brake device can besecured'. j The control of the exhaust is desirable,jfor example,

in, a high lead yarding system Where the logs are hauled from a distance toa v point nearl the spar or tree. As the log approaches, it is elevated. By Aslipping the friet-ion, the log is easily dropped without jar to the rigging. In the absence-of the but it can be made to control- 'the exhaust of fluid pressure therefrom.

controt of the exhaust, the log would; be

permitted to drop suddenly, thereby causing whipping of the spar and a general wrenching and strain on the rigging.

By normally admittii'igv a limited amount of steam to the respective cylinders, and in an amount .insufficient to operate the pisthe cylinders and the pistons are maintained in a warm conditiont-h-rough leakage of the steam. When the cylinder is cold, there may be a delay the operators valve is thrown lover into contact with its drlving gear or before the friction brake is properly applied. But when the cylinderpis.ton and pipes are well heated up, the application .takes place in a fraction of a second,

which, of course, is highly advantageous,

particularly vwhere the fluid pressure oper- 4 4ated device is used in connection with hoisting or logging apparatus and other similar of several seconds after is open before'the drum apparat-us where the fluid pressure operated device should promptly be applied. So long as there is a circulation of steam passing through the pipe and cylinder,

and associated parts arev maintained at the required Vtemperature sothat the device to which the piston is connected may properly be operated.l Preferably, the pistons are so constructed and arranged, by .applying a less number ofy packing rings than have hitherto commonly been used, so as to permit a limited amount of leakage normally the cylinder,

to take place. Furthermore, by normally admitting a limited amount of steam continuously to the cylinder and thus preheating the same, condensation in the cylinder is prevented, and delays in application are reduced.

Brieiy stated, when the manually op erated lever 8l is thrown hard over to the right, steam enters freely into one of the cylinders to operate the piston and when it is thrown hard over to the left, steam is freely admitted to the other cylinder to operate its piston. When the lever is in its neutral position, the valves' are preferably so adjusted and arranged that there is steam pressure in both cylinders of say, five pounds, where the operating pressure may be 100 to 150 pounds, the small steam pressure being sufiicient to force a circulation of steam around the piston, filling the cylinder and out through the pipe system and thus maintaining the heat in the cylinders land preventing condensation. Under these conditions, whenever it is desirable to operate either the brake or the friction device, the operation will take place in a fraction of a second, rather than taking place in several seconds of time, as has been common.

It has been found in practice'that a new cylinder and piston even provided with three or four piston rings, and of ordinary machine construction, leaks sufficiently to satisfy the demand-for sufficient steamto preheat the cylinder. This fact is common to all steam pistons which only become relatively steam tight through the normal proc-l ess of wearing in After a longperiod vof wear, in case the leakage is insujiicient,

the operator will increase this leakage by any wellknown expedient, as, for example, by the removal of one of the piston rings.

While I have illustrated my invention in connection with a fluid pressure operated friction device and a Huid pressure operated brake, it will, of course, be understood that the same is not limited thereto and is applicable to the operation of either of these devices, singly,vor,in fact, to the operation of any iiuid pressure operated device where the yheated fluid under pressure is admitted to the cylinder to actuate a piston and'operate the device, and the release of the fluid pressure causes the piston to move in the opposite direction to release the device.

1. In combinatioma fluid pressure operated device comprising a cylinder and piston, the piston being constructed and, -ar

ranged `to permit steam normally to leak past the same in' suiicient amount to maintain the cylinder heated, a control therefor I located in a space occlplild by the operator,

means for normally a 'tting tothe cylinder steam suiicient vin amount to warm the same but insulicient to operate said device,

and means for conducting thel steam leaking past said piston to a point remote from the space occupied by the operator.

2. In'combination, a fluid pressure'oper'- ated device comprising a cylinder and its piston, the piston being constructed and arranged to permit ,steam normally to leak past the same in sufficient amount to maintain the cylinder heated, a device operated by said piston in one direction of movement and released by movement thereof in the opposite direction, a, ipe connected tothe central portion of sai piston and arranged axially with said cylinder .and communicating with the side of the piston remote from that side to which steaml is admitted and leading to exhaust, and means providing an annular space around said pipe through which steam is admitted to said cylinder.

3. In combination, a Huid pressure operated device comprising a rotary cylinder l audits piston, the piston being constructed and arranged to permit steam normally to leak past the same in sufficientamount to maintain the cylinder heated, a device oper-l ated by said piston in one direction of movement and released by movement thereof in the opposite direction, a pipe connected ,to the central portion of said piston and arranged axially with said cylinder and communicating with the side of the piston remote Afrom that side to which steam is admitted and leading to exhaust, and means providing an annular spacearound said pipe `through vwhich steam is admitted to said cylinder. f 1

4. In combination, a liuid pressure operated device comprising a cylinder and its piston, the piston being constructed and arranged to permit steam normally to leak past the same in sufficient amount to mainllU whichsteam is admitted' and leading to exn haust, and means for conducting the steam leakin past the Vpiston to a point` remote from t espace occupied by the operatcr.

5. fIncombination, a fluid pressure o erated device comprising a cy inder an itspiston, the piston being constructed and arranged to permit steam normally to leak past the same in suiiicient amount to maintain the cylinder heated, a control device therefor'located ina space occupied by the operator, a device operated by said iston,

in one direction of movement and re eased by movement thereof in the opposite dir ection, a` pipe connected tothe central portlon ne@ j 6. In combination, a fluid pressure oper-- ated device comprising a piston and cylinder, the piston being constructed and arranged to permit steam normally to leak past the same in sulicient amount to maintain the cylinder heated, a source of fluid under pressure, a conduit for conducting said luid to said cylinder, a valve member interposed-Within said conduit for controlling the flow of fluid to said cylinder and constructed and arranged in one position to admit to the cylinder steam sufficient in amount to maintain the heat of the same by leakage past the piston, but insuliicient .to operate said device, and in another position to admit to said cylinder steam suflicient in amount to operate said device, and means for operating said valve to either of said positions.

7. In combination, a fluid pressure operated device comprising a cylinder and its piston, the piston being constructed and arranged to permit steam normally to leak past the-.same in sufficient amount to maintain the cylinderheated, yielding means resisting the movement of said pistonl in one direction, a source of fluid under pressure, a conduit for conducting said fluid to said cylinder, a ,valve member interposed in* said conduit for controlling the flow of fluid to said cylinder and constructed and arranged in one position to admit to the cylinder steam-suiiicient in amount to maintain the heat of .the same by leakage past..

thepistombut insuicient to operatesaid device by movement of the piston against the force of said yielding means, and` in another position to admit to saidl cylinder steam suflicient in amount to operate said device by movement of the piston against said yielding means, and means for operating said valve to 'either of said positions.

8. In a single acting Huid pressure operated device comprising a Apiston and cylinder, the piston being constructed and arranged to permit steam normally to leak past the same in sulicient. amount to maintain the cylinder heated, a -source of i'luid under pressure, a conduit for connecting said iuid to said cylinder at one side of said piston and to push the same in one direction only, a valve member interposed Within said conduitfor controlling the flow of fluid to said cylinder and constructed and arranged in one position to admit to the cylinder steam suiicient in'amount to maintain the heat of the same'by leakage past.

the piston, but insuilicient to operate said device, and in another position to admit to said cylinder steam sufficient in amomt to operate said device, means for .operating said valve to either of said positions, and

means comprising a separate continuously open conduit for leading the steam so lealiing past the piston to a point where the vapor of said steam may not cloud the vision of the operator of said device.

9. In combination, a fluid pressure operated'.device comprising a cylinder and piston, the piston being constructed and arranged to permit steam normally to leak past the same in sufficient amount to maintain the cylinder heated,a control therefor located in a space occupied by the operator,

means for normally admitting to the cylin,

der steam sufficient in amount to Warm the same but insufficient to `operate said device, and means. for conducting the steam leaking -past said piston from the cylinder.4

THOMAS SPENCER MILLER. 

